【 Weak current College 】 thermocouple technology standards 】

<br> <br> (S-type thermocouple) 10-Platinum and rhodium thermocouple <br> 10-Platinum and rhodium thermocouple (S-type thermocouple) for precious metals thermocouple. Even the provisions 0.5mm diameter, tolerance-the cathode 0.015 .mm (SP) of nominal chemical composition as rhodium alloys, which contain 10% rhodium, Platinum is 90%, negative pole (SN) is a pure Platinum, rhodium thermocouple is commonly known as sin. The thermocouple long-term maximum use temperature is .1300 ° c, short-term maximum use temperature of 1600 ° c. <br> S-type thermocouple in thermocouple series with maximum accuracy, stability, temperature measurement and temperature district wide, long life and other advantages. Its physical, chemical, thermal .potential good performance and stability in high temperature oxidation resistance, suitable for oxidizing and inert atmosphere. Because an s-type thermocouple with excellent overall performance, in line with the international temperature scale of use S-type thermocouples, for a long time had as the .international temperature scale of interpolation instrument, "Although" provides future ITS-90 as the international temperature scale of international instruments, but check the temperature of the Advisory Committee (CCT) that S-type thermocouple can still be used for approximate realization of the international .temperature scale. <br> S-type thermocouple deficiencies is thermoelectric power, the smaller thermal potential rate, sensitive reading of low, high mechanical strength, is very sensitive to pollution, expensive precious metal materials, resulting in a large one-time investment. .(R-type thermocouple) 13-Platinum and rhodium thermocouple <br> 13-Platinum and rhodium thermocouple (R-type thermocouple) for precious metals thermocouple. Even the provisions 0.5mm diameter, tolerance-the cathode 0.015mm (RP) name of .chemical constituents for RH alloy, of which 13% with rhodium, Platinum is 87%, negative pole (RN) is a pure Platinum, long-term maximum use temperature is 1300 ° c, short-term maximum use temperature of 1600 ° c. .<br> R-type thermocouple in thermocouple series with maximum accuracy, stability, temperature measurement and temperature district wide, long life and other advantages. Its physical, chemical, thermal potential good performance and stability in high temperature oxidation resistance, suitable for oxidizing and .inert atmosphere. As a result of R-type thermocouple integrated performance and S-type thermocouple is, in my country has been difficult to promote, subject in fathoming on imported equipment has been applied, the internal temperature is rarely used. 1967-1971, .United Kingdom United States NBS and NPL, NRC Canada three research institutions conducted a collaborative research, the results indicate that the R-type thermocouple's stability and reproducibility than S-type thermocouple are good, my country has not yet been carried out research in this field .. <br> R-type thermocouple deficiencies is thermoelectric power, the smaller thermal potential rate, sensitive reading of low, high mechanical strength, is very sensitive to pollution, expensive precious metal materials, resulting in a large one-time investment. <br .> <br> (B-type thermocouple) 6 30-RH rhodium thermocouple <br> 6 30-RH rhodium thermocouple (B-type thermocouple) for precious metals thermocouple. Even the provisions 0.5mm diameter, tolerance-the cathode 0.015mm ( .BP) nominal chemical composition as rhodium alloy, of which 30% with rhodium, Platinum is 70%, negative (BN) as rhodium alloy, including the amount of 6% RH to, commonly known as double-rhodium thermocouple. The thermocouple long- .term maximum use temperature of 1600 ° c, short-term Max temperature is 18 degrees centigrade. <br> B type thermocouple in thermocouple series with maximum accuracy, stability, temperature measurement and temperature district wide, long life, high temperature limit. Applicable to .the activity of and inert atmosphere, can also be used for vacuum in the short term, but not to restore a climate of or containing metals or metal vapour atmosphere. B type thermocouple one obvious advantage of not having to compensate with compensating cables, because 0 .~ 50 ° c range thermoelectric power of less than 3 μ V. <br> B type thermocouple deficiencies is thermoelectric power, the smaller thermal potential rate, sensitive reading of low, high mechanical strength, is very sensitive to pollution, expensive precious metal materials ., resulting in a large one-time investment. <br> <br> (K-type thermocouple) NI-CR-NI-SI-thermocouple <br> NI-CR-NI-SI-thermocouple (K-type thermocouple) is .by far the largest amount of low-consumption of metal, the thermocouple to the sum of other thermocouple. Cathode (KP) nominal chemical composition: Ni: Cr = 90: 10 to the negative (KN) of nominal chemical composition: Ni: Si .= 97: 3, its working temperature is-200 ~ 1300 ℃. <br> K-type thermocouple with good linearity, thermal electromotive force is big, high sensitivity, stability and uniformity is good, strong oxidation resistance, low price, etc. ., can be used in oxidizing, inert atmosphere. Widely used for the user. <br> K-type thermocouple cannot directly at high temperatures for sulphur, or restore, oxidation alternating atmosphere and vacuum, nor recommended for weakly oxidizing atmosphere. <br> .<br> (N-type thermocouple) SI-CR-NI-SI-thermocouple <br> SI-CR-NI-SI-thermocouple (N-type thermocouple) Lim metal thermocouple, is one up-to-date international standardized thermocouple ., is in the early 1970s by Australia of Defense Laboratories developed by it overcomes K-type thermocouple's two major disadvantages: K-type thermocouple in 300 ~ 500 ℃ room because of the NI-CR alloy lattice short range ordered due to thermal electromotive force is .not stable; in 800 ¡ .æ occurring as a result of NI-CR alloy preferential oxidation induced thermal electromotive force is not stable. Cathode (NP) of nominal chemical composition: Ni: Cr: Si = 84.4: 14.2: 1.4, anode (NN) nominal chemical composition: Ni .: Si: Mg = 95.5: 4.4: 0.1, its working temperature is-200 ~ 1300 ℃. <br> N-type thermocouple with good linearity, thermal electromotive force is big, high sensitivity, good stability and evenness, oxidation resistance, cheap ., free from the influence of short-term and other advantages, its overall performance is better than K-type thermocouple, is a very promising thermocouple. <br> N-type thermocouple cannot directly at high temperatures for sulphur, or restore, oxidation alternating .atmosphere and vacuum, nor recommended for weakly oxidizing atmosphere. <br> <br> (E-type thermocouple) nickel-copper-nickel thermocouple <br> Nickel-chromium-CU-NI thermocouple (E-type thermocouple) also known as NI .-CR-constantan thermocouple, is also an inexpensive metal of thermocouple, cathode (EP): NI-CR-10 alloy, the same chemical composition and KP, anode (EN) is a copper-nickel alloy, nominal chemical composition: 55% .of copper, nickel, and 45% of the amount of iron, manganese, cobalt, and other elements. The use of the thermocouple temperature-200 ~ 900 degrees centigrade. <br> E-type thermocouple thermal electromotive force of sensitivity high is the .highest of all thermocouple, preferably made of thermopile, measurement of small temperature variations. For high humidity atmosphere of corrosion, less sensitive to humidity high environment. E thermocouple also has good stability, oxidation resistance, superior to copper-constantan thermocouple Fe-cuni, .price, etc., and cannot be used in oxidizing, inert atmosphere is widely used for the user. <br> E-type thermocouple cannot directly at high temperatures for sulphur, atmosphere, thermoelectric uniformity. <br> <br> (J- .type thermocouple) iron-copper-nickel thermocouple <br> Fe-Cu-Ni thermocouple (J-type thermocouple) also known as the Fe-cuni thermocouple and a cheap inexpensive metal of the thermocouple. Its cathode (JP), on behalf of .constituents as pure iron, anode (JN) copper-nickel alloy, often been unequivocally call cuni, its nominal chemical composition: 55% of copper and nickel as well as 45% of a small but very important manganese, cobalt, iron, and other .elements, even though it called cuni, but different from the NI-CR-constantan and copper-constantan of constantan and therefore cannot be used to replace EN and TN. Fe-cuni thermocouple measurement temperature region of coverage as-200 ~ 1200 ° c ., but usually use a temperature range of 0 ~ 750 ° c <br> J-type thermocouple with good linearity, thermal electromotive force is big, high sensitivity, stability and uniformity is good, inexpensive, and other advantages, widely used by the user .. J-type thermocouple can be used to vacuum, oxidizing, reducing, and inert atmosphere, but the anode oxidation of iron under high temperature, the faster the temperature limit, nor direct unprotected under high temperature atmosphere for curing. <br> <br .> (T-type thermocouples) CU-Cu-Ni thermocouple <br> Brass-copper-nickel thermocouple (T-type thermocouples) also known as copper-constantan thermocouple and a best measurement at low temperature in metal of thermocouple. Its cathode ( .TP) is pure copper, anode (TN) is a copper-nickel alloy, often as cuni, and NI-CR-constantan of constantan EN General, and Fe-cuni-constantan JN cannot be generic, even though they are called cuni, .CU-Cu-Ni thermocouple measurement temperature area to cover-200 ~ 350 ℃. <br> T-type thermocouples with good linearity, thermal electromotive force is big, high sensitivity, stability and uniformity is good, inexpensive, and other advantages, in .particular in-200 ~ 0 ℃ temperature use, better stability, stability may be less than ±, 3 V, low μ assays can be used as the standard for low-volume value. <br> T-type thermocouples cathode copper oxidation resistance at .high temperatures, poor performance of operating temperature limit is restricted. <br> <br>.